1. Technical Field
The present invention generally relates to technology for performing visible light communication. More particularly, the present invention relates to technology for performing visible light communication using electrically switchable glass and a conventional light source that is incapable of visible light communication.
2. Description of the Related Art
Conventional visible light communication could have a light source which is capable of visible light communication because modulated signals are directly applied to the light source, whereby data is transmitted to lighting output.
General lighting, which is used only to illuminate dark areas, is incapable of being used for visible light communication. Also, lighting devices that include various commonly used light sources and do not include a visible light communication function, (for example, fluorescent lamps, light bulbs, LEDs, OLEDs, metal-halide lamps, and the like), cannot perform visible light communication.
Meanwhile, electrically switchable glass is glass for adjusting brightness by controlling the light transmissivity thereof when voltage is applied thereto. Such glass is commonly known as a “smart window” or “smart glass”. Generally, electrochromic glass, suspended particle device glass, and Polymer Dispersed Liquid Crystal (PDLC) glass may be used for a “smart window” or “smart glass”, but without limitation to these examples, various types of electrically switchable glass may be used.
Also, the material for the so-called “smart glass” is not limited to glass. Smart glass may include glass having attached thereto synthetic resins and a material that may adjust brightness by changing the amount of light that passes through the material when voltage is applied thereto.
However, because such smart glass is merely used to adjust the amount of light output from an external light source, it cannot perform visible light communication.
Korean Patent Application Publication No. 2013-0101617 discloses technology in which a server provides additional information to a visible light communication terminal through visible light communication.
Korean Patent Application Publication No. 2013-0101617 discloses technology for turning on or off radiation of a specific frequency from a light source in order for the light source that outputs visible light to perform visible light communication, but does not disclose technology for performing visible light communication using conventional light sources which are incapable of visible light communication.
Therefore, considering that visible light communication has become more important recently and that light sources capable of visible communication are relatively expensive compared to conventional light sources which are incapable of visible light communication, it is necessary to provide technology for performing visible light communication using conventional light sources which are incapable of visible light communication.